T 0765/12 - Two strontiums salts

Key points

• In this opposition appeal. the Board agrees with inventive step of a product claim for a pharmaceutical tablet, being a tablet or capsule, "comprising only two strontium salts, wherein said strontium salts consists (sic) of strontium carbonate and strontium chloride" . Good to see that you can still get a pharmaceutical product claim (i.e. for any disease) with two inorganic salts as active ingredient.
• The Board is also careful about what the closest prior art D6 teaches, and does not stop at the abstract.
• " The title of [D6] is "Effects of Low Doses of Strontium on Bone Quality and Quantity in Rats". In the abstract it is stated that strontium has been shown to increase bone mass when given at low doses (abstract, first and last sentences). However, the information gained from the experimental section of D6 does not support such a finding:" (follows an analysis of the experimental results in D6). In sum, from the data provided by D6, which partly show non-significant findings, it is not clear how strontium, especially strontium chloride, will influence bone and cartilage disorders, specifically those that require strengthening of the bone material. D6 merely conveys the message that administration of strontium chloride may affect bone formation and resorption..
• Therefore, the claimed subject-matter is inventive in view of D6. 

Claim 1 of the Main Request
"1. A pharmaceutical composition comprising only two strontium salts, wherein said strontium salts consists (sic) of strontium carbonate and strontium chloride for oral administration in the form of a tablet, a capsule, or a dissolvable tablet."



EPO T 0765/12 - link

3.2 Inventive step

The present invention relates to pharmaceutical compositions intended for use in the treatment of cartilage and bone disorders, especially for use in the treatment of osteoporosis (paragraphs [0001] and [0009]). Specific strontium salts are used to provide an active ingredient having high availability and fewer side-effects (paragraph [0012]). In particular, the combination of strontium chloride and strontium carbonate has been found to be advantageous (paragraph [0050], examples 2 to 4, 6, 7, 11, 12 and 17, claims 5 to 8 as granted).

During the opposition proceedings and in appeal proceedings the only document discussed as the closest prior-art document and thus as a promising starting point for the skilled person is document (6).

The title of document (6) is "Effects of Low Doses of Strontium on Bone Quality and Quantity in Rats". In the abstract it is stated that strontium has been shown to increase bone mass when given at low doses (abstract, first and last sentences). However, the information gained from the experimental section of document (6) does not support such a finding:

[...]

The experimental findings of document (6) are then analysed in view of other referenced scientific articles (pages 317 and 318). It seems to be clear from this discussion that bone mineralisation is negatively affected by the administration of strontium, whereas osteoblast surface is not diminished (page 317, left column, last paragraph). These findings lead the authors of document (6) to speculate about the influence of a possible calcium supplementation (page 317, right column, first paragraph, last seven lines).

In sum, from the data provided by document (6), which partly show non-significant findings, it is not clear how strontium, especially strontium chloride, will influence bone and cartilage disorders, specifically those that require strengthening of the bone material. Document (6) merely conveys the message that administration of strontium chloride may affect bone formation and resorption.

The problem underlying the patent in suit must thus be formulated as how to provide a composition for the treatment of bone and cartilage disorders.

The proposed solution is the provision of tablets, capsules or dissolvable tablets comprising strontium chloride and strontium carbonate.

Starting from document (6) the skilled person might have considered conducting further tests relating to the use of strontium chloride in the treatment of cartilage and bone disorders. The skilled person could, for example, take up the suggestion of document (6) to investigate the action of strontium chloride on bones when given in combination with a calcium supplement. There is however no straightforward and clear teaching in document (6) on a direct link between the administration of strontium chloride and physiologically significant effects on bone. It is thus not possible to assert that the skilled person would have administered strontium chloride in the hope of successfully treating a bone or cartilage disease. Since it cannot be clearly established what action the skilled person would have taken when considering document (6), it is not necessary to establish whether the skilled person would have added a further strontium salt, particularly in the form of strontium carbonate, to the tablets, capsules or dissolvable tablets for administration to a patient suffering from a bone- or cartilage-related disease.

The subject-matter of claim 1 is thus not obvious when starting from document (6) as the closest prior art.

The same line of argument applies mutatis mutandis to the subject-matter of independent claims 8, 16, 17 and 21, which also involve an inventive step when starting from document (6) as the closest prior art.